In the field of medicine, the requirement for the control of flow of fluids from high to low pressure volumes is required in many organs. Disorders of control of flow produce medical conditions for which medical or surgical treatment is required. Heretofore medical and surgical interventions have associated side effects and complications that prevent the conditions from being adequately treated.
A specific example is urinary incontinence which is a common condition whereby the orderly outflow of urine from the bladder into the urethra is disordered by anatomical and neural disorders. The American Urological Association states as follows:                “urinary incontinence is the involuntary loss of urine. It is not a disease but rather a symptom that can be caused by a wide range of conditions. Diabetes, stroke, multiple sclerosis, Parkinson's disease, some surgeries or even childbirth can cause incontinence. More than 15 million Americans, mostly women, suffer from incontinence. Although it is more common in women over 60, it can occur at any age. Most health-care professionals classify incontinence by its symptoms or circumstances in which it occurs. In the normal population, the incidence of incontinence in females over 65 is more than 25 percent and in males it is about 15 percent”        
This dysfunction produces a requirement for the use of diapers, pessaries, medications and surgical procedures that are not successful in controlling the condition in a large number of patients. One such procedure involves implantation of an artificial sphincter, in the form of a patient-controlled device made of silicone rubber with an inflatable cuff that fits around the urethra, (the tube through which urine leaves the bladder). A balloon regulates the pressure of the cuff, and a bulb controls inflation and deflation of the cuff. The balloon is placed within the pelvic space, and the control bulb is placed in the scrotum of a male or the external vaginal lips of a female. The cuff is inflated to keep urine from leaking. When urination is desired, the cuff is deflated, allowing urine to drain out.
Numerous other medical conditions exist in which fluid control is required such as hydrocephalus glaucoma and the like which will be described more fully later.